Method and apparatus for controlling the diameter of glass fibers

ABSTRACT

A glass fiber strand forming process which employs a computer to monitor a plurality of fiber forming positions and indicate whether the fiber diameter is correct and whether or not a process variable change should be made before the next fiber forming run is begun. The computer also gives a signal to categorize each forming package according to a plurality of weight categories. This process is accomplished by an apparatus having a bushing for supplying molten streams of glass, a winder for gathering the fibers which supplies a pulse input to a computer to record the running time, a conveyor to transport formed packages to a weight scale. The scale is connected to the computer to send a weight signal thereto whereas a signal is generated and is sent to the bushing to control the temperature of the bushing and the diameter of the forming fibers.

United States Patent Jensen et al.

[ Mar. 28, 1972 [72] Inventors: Thomas H. Jensen, Murrysville, Pa.;

Howard M. Bennett, Lexington, N .C.

3,096,837 7/1963 Abbott et a1 ..177/119 X 3,218,138 11/1965 Mennerich.... ..65/2 3,265,476 8/1966 Roberson ..65/ll W X Primary Examiner-S. Leon Bashore Assistant Examiner-Robert L. Lindsay, Jr. Attorney-Chisolm and Spencer A ItuNNINo TIME [73] Assignee: PPG Industries,1nc., Pittsburgh, Pa.

[22] Filed: Aug. 26, 1970 [57] 1 ABSTRACT [21] Appl. No.: 67,260 A glass fiber strand forming process which employs a computer to monitor a plurality of fiber forming positions and in- Related US. Applica n Da dicate whether the fiber diameter is correct and whether or [63] Continuation of Ser No 702 331 Feb 1 1968 aban not a process variable change should be made before the next doned fiber forming Tunis begun. The computer also gives a signal to categorize each forming package according to a plurality of [52] U 8 CI 65/2 65/11, 65/29 weight categories. This process is accomplished by an apf 65/158 paratus having a bushing for supplying molten streams of [51] Int Cl b 37 glass, a winder for gathering the fibers which supplies a pulse 58] Fieid 1 w 29 input to a computer to record the running time, a conveyor to 58 transport formed packages to a weight scale. The scale is connected to the computer to send a weight signal thereto whereas a signal is generated and is sent to the bushing to con- [56] Reerences Cited trol the temperature of the bushing and the diameter of the UNITED STATES PATENTS formmg fibers- 702,634 6/1902 Coleman 177/60 10 Claims, 3 Drawing Figures BUSIyENEG TEM ATURE i =1 coNTeoI. 5+

[ MANUAL PAC KAOE 0 0k WEIGHT AUTOMATIC SIGNAL. ADJUSTMENT k CALL DOWN c SIGNAL 4- 2 POSITION TYPEWRITEIE IDENTIFICATION COMPUTER FOR WEIOHINO 4g przooucrloN QEPORT B PULSE INPUT (mm) PRODUCT INFORMATION cone F DATA ENTRY PANEL PATENTEU MAR 2 8 I972 SHEET 2 BF 3 INVENTORS v ATTORNEY 5 METHOD AND APPARATUS FOR CONTROLLING THE DIAMETER F GLASS FIBERS This application is a continuation of Ser. No. 702,331, filed Feb. 1, l968,now abandoned.

The present invention is concerned with a fiber forming process wherein thermoplastic fibers are continuously attenuated from a source of molten thermoplastic material and it has particular relation to the production of continuous filament glass fibers which are drawn from a bushing and are would on a rotating forming tube.

In the conventional process, continuous filament glass fibers are made in strand form by drawing a plurality of glass filamerits through orifices in an electrically heated, platinum alloy bushing. The filaments are gathered together in the form of a strand and the strand is would upon a forming tube mounted on a rotating cylinder called a collet. At the beginning of the fiber forming process, an operator pulls the individual filaments from the bushing by hand and groups them into a strand. The strand is passed over a gathering guide and is wound around one end of the collet beyond the forming tube. Rotation of the collet and forming tube is then begun. It takes several seconds for the collet to come up to the proper drawing speed and during this time the strand which is formed is of too great a diameter. When the proper drawing speed is attained, the strand is moved onto a traverse such as shown in U.S. Pat. No. 2,391,870. The strand is shifted by the traverse lengthwise of the tube so as to be wound during the remainder of the run on the tube in an area which is spaced from the strand formed on the end of the collet during the start-up. When the forming run is completed, the strand is returned to the end portion of the collet containing the strand formed during start-up and wound thereon as the collet rotation returns to zero.

There is no twist in the strand as it is thus formed and a size is applied to the filaments prior to the winding of the strand on the tube in order to bond them together and maintain the integrity of the strand. An open wind has been used on the forming tube in order to aid removal of the strand from the tube. With this type of wind the succeeding turns of strand cross each other at substantial angles. The spiral wire traverse shown in U.S. Pat. No. 2,391,870 has proved to be satisfactory for traversing a strand at the high rate of speed which is employed to wind the strand on a forming tube. The attenuating speed of the strand is usually about 10,000 to 15,000 f.p.m. The traverse, in addition to rotating about its own axis to provide a 3 to 5-inch throw per rotation, is reciprocated axially in order to distribute the strand over the length of the forming tube. The forming package produced with this type of traverse is barrel-like in shape with the ends of the package being tapered to substantially a single thickness of strand and with the center having the maximum diameter and thickness of package.

There are several factors such as glass head above the bushing, glass temperature and speed of drawing which influence the size of the diameter of the strand during the fiber forming run. If these factors can all be kept constant during the run, a fiber of uniform diameter from the beginning to the end of the run can be produced.

it is conventional to use a collet and forming tube which rotate at a constant r.p.m. It can be seen that as the amount of strand is built up on the forming tube, the peripheral speed of the forming package increases during the fiber forming run and consequently the drawing speed of the strand is increased. Thus, unless there is some compensation made during the run to one of the variables mentioned above, the diameter of the strand formed at the end of the run will be smaller than the diameter of the strand formed during the beginning of the run.

Several methods have been suggested to solve the diameter size problem caused by rotating the collet at constant r.p.m. One method has been to increase the temperature of the molten glass in the bushing gradually during the fiber forming run, thereby gradually increasing the fluidity of the glass and permitting more glass to be attenuated as the run progresses. Another method has been to decrease the r.p.m. of the collet gradually during the run so as to maintain the peripheral speed of the forming package constant while the glass temperature is maintained constant. Both of these methods are discussed in some detail in U.S. Pat. No. 3,256,079.

The above-mentioned methods are designed to insure that the diameter of the fibers in a forming package is substantially the same throughout the length of the fiber on the forming package. Establishing equipment settings to control these variables does not necessarily insure that a fiber of proper diameter is being made. Other conditions such as forming room air temperature, improper functioning of equipment and the like may result in the production of fibers which are greater or smaller in diameter than desired.

At the present time, the fiber diameter is checked in a commercial fiber forming operation by weighing a measured length of strand taken from a forming package. This provides a number in terms of yards per pound which is conventionally termed yardage" of the fiber. This in effect is the figure used to identify the fiber diameter. This is usually done once for each fiber forming station during an 8-hour shift by a person in the plant quality control laboratory. Thus it can be seen that it is possible for a particular fiber forming station to be producing fibers of improper diameter for almost 8 hours before this mistake is discovered. By this time, the forming packages from this station have become intermingled with other forming packages for the same yarn count and it is extremely difficult to segregate them. The magnitude of the difficulty presented by not knowing if proper filament size yarn is being produced is dependent upon the extent of the diameter variation and the amount of improper strand produced.

In accordance with the present invention, selected variables in the fiber forming operation are monitored during the fiber forming run by a computer. The computer provides a signal at the end of the forming run which indicates whether or not the diameter of the fiber being formed is within the specification. The signal indicates whether the fiber diameter is too large or too small and gives an approximation of the magnitude of the variation from the specified standard and an indication of which monitored variable should be changed. This change can be made manually by an operator or the computer can be programmed to make the necessary changes. For example, if the computer indicates that the glass temperature in the bushing is too low, the bushing temperature control can be adjusted manually or by asuitable computer signal to raise the bushing temperature according to a programmed temperature-fiber diameter relationship.

In a typical example of the invention which may be considered the best mode of performing the invention, the computer is programmed to monitor the winder speed (r.p.m.), time of forming run, down time and weight of strand on the forming package. The information concerning time of forming run, winder speed and weight of strand on the package provides information for calculating the fiber diameter. The information about the winder speed shows the operating condition and whether it is varying from the preset condition. If it is not, and the fiber diameter is not as desired, then a change to the bushing temperature control can be made manually or by the computer to change the fiber forming operation to produce fibers of proper diameter. The bushing temperature can also be monitored if desired, but normally this is not necessary for the bushing temperature control itself provides accurate data as to the bushing temperature.

A further embodiment of the invention resides in the determination by the computer of the weight of each package and the giving of a signal which categorizes the weight of the package as being, for example a one-fourth, one-half, threefourth full, or overweight package. With this information, the forming operator is able to route the forming package to the proper end-finding station. This simplifies later handling of the forming packages with respect to directing them to the subsequent fabrication locations for twisting, plying, rewinding, heating, moisture conditioning, chopping or other treatment.

The details and advantages of the invention are further described in conjunction with a description of the drawings in which:

FIG. 1 is a diagrammatic view of the fiber forming operation;

FIG. 2 is an elevation illustrating apparatus, exclusive of the computer, for performing the invention; and

FIG. 3 is a graph illustrating the method of calculating the actual winder speed operating curve and comparing it with the programmed winder speed curve.

ln FIGS. 1 and 2 there is shown a fiber forming arrangement consisting of a bushing mounted at the bottom of an opening 11 in a forehearth 12 of a glass tank (not shown). The bushing is made of a platinum-rhodium alloy and is heated electrically by electric current passing through bus bars 15 mounted at opposing ends of the bushing.

Molten glass 17 is supplied to a plurality of bushings 10 from a glass tank (not shown) through the forehearth l2 and a plurality of openings 1 1 in the forehearth 12. The molten glass 17 in the bushing is heated to a suitable temperature for fiber forming by means of the heat conducted from the bushing. The bushing is heated by electrical current passing through the walls of the bushing. The molten glass 17 flows through tips 18 located in the bottom of the bushing and forms in small cones suspended from the tips 18. The tips are aligned in rows having a great many tips in each row so as to provide a total number of tips ranging, for example, from 200 tips to 1,600 tips in a single bushing.

Individual glass fibers 26 are pulled from the cones 25 at a very high rate of speed, for example, 5,000 to 20,000 f.p.m., usually about 10,000 to 15,000 f.p.m., and wound on a rapidly rotating forming tube 28 mounted on a collet 29. The collet may be approximately 6 to 8 inches in outside diameter and may rotate at approximately 6,000 to 8,000 rpm, depending upon the size of the fiber to be produced and other operating conditions such as the temperature of the glass in the cones 25. The glass fibers 26 are grouped into a strand 30 as they pass over a guide 32 prior to being wound on the forming tube 28.

Usually an aqueous size containing a liquid binder and a lubricant, such as a combination of starch and a vegetable oil, is applied to the individual fibers 26 of the strand 30 as they pass a moving size applicator 33 which is mounted just above the guide 32. The applicator may be in the form of a rotating roller 34 or moving belt having a film of the size applied to it. The filaments pass over the roller or belt at some tangential point for momentary contact with the sizing solution to transfer the solution from the applicator to the filaments. An example of a suitable size applicator is shown in US. Pat. No. 2,873,718.

As the strand 30 is wound on the tube 28, it is traversed along a portion of the length of the tube by means of a conventional high speed traverse device 35 and by means of relative axial reciprocation of the collet 29. The above description applies to conventional glass fiber strand forming. Further details of a conventional, commercial installations showing multiple fiber forming stations in a plurality of forehearths are set forth in US. Pat. No. 3,321,290.

The diagrammatic view of FIG. 1 illustrates the interrelation of a commercially available, digital, process control (real time) computer to the strand forming apparatus just described. For example, General Electric Company's GE-4020 process computer can be used as computer 40. The computer monitors all factors which are necessary to maintain a full-time monitor of all factory operating positions. The computer is programmed with fixed information including mathematical relationships which govern the processing of the input data to provide bushing temperature correction and package weight information. The computer provides infonnation to production personnel to enable them to make bushing temperature, winder speed, forehearth and/or tank adjustments. The computer categorizes forming packages according to weight and good or bad yardage. By means of internal data storage and proper accumulation of input data over an eight hour period of operation, a shift report is produced with presents all the various factors for assessing the total performance of the factory forming operation.

An integral part of the data processing are tests for significant abnormal process factors such as winder speed, weighing device, position of weighing device, package weight and'fiber diameter which are alarmed and typed out by typewriter 42, as well as tests to insure proper operator procedure. The computer is programmed with all relevant information regarding each of the products to be produced such as starting speed, rate of change of winder speed, limits of deviation from desired winder speed and yarn speed. This infonnation includes standard winder speed information, fiber diameter and number, limits of acceptable fiber diameter variation, fiber diameter-bushing temperature conversion factor, sizing code, percent by weight of sizing and water, standard call down time and weight of forming tube. This information is internally organized into tables by product, each table having a code designation. Through the data entry panel (DE?) 44, the proper code designation is established in memory for each operating position thus defining all the fixed factors required for the system to process the data from each position. As product changes are made, code designations are correspondingly changed within the computer memory through the DEP 44. These memory locations are automatically scanned every 15 minutes to keep a current tabulation of number of positions by product.

The information regarding the forming operation is generated from five inputs from each position to the computer. These are as follows:

A. A scan of the relay contact of the motor circuit of each traverse device 35 once each second to indicate a running or down status with one second accuracy.

B. An accumulation of the time intervals between a specified number of successive pulse outputs from a proximity switch on each winder once every 5 minutes to measure collect speed (r.p.m.).

C. An operator-actuated push button contact 48 which will stop winder collet 29, call the load cell to the position and identify the load cell input with the particular position. Separate buttons can be provided for stopping the winder and calling the load cell. This would permit the operator to stop the winder without calling the load cell in case of a need to stop the winder prematurely without having a package to weigh. Altemately the winder can be stopped separately by a conventional foot pedal switch (not shown).

D. A request signal operated manually at location 45 by the forming operator to weigh the forming package 46 on load cell 47.

E. A reading by the computer of the signal from load cell 47 representing the weight of package 46. In addition, product code information (F) is established in the computer memory through the DE? 44 for each product. This information is assigned by the computer to each winder position according to the code of the product being produced at that position.

The computer outputs are hereinafter described in conjunction with a description of the sequence of events in the fiber forming operation for a particular fiber and strand description. The operation is now described beginning with a particular winder which is not running. The non-running status of the winder is sensed through input A corresponding to a non-energized traverse motor circuit. The computer accumulates down time for this winding position in memory until the traverse motor circuit is energized. Pulse counts monitored on a one second basis from an internal computer clock, i.e., an oscillator in the computer, provide the information for the accumulation of the down time.

When the collet gets up to proper winding speed, the traverse motor starts and the computer stops accumulating down time and begins to accumulate running time by means of pulse counts from the computer clock. These pulse counts are directed to a different portion of the computer memory which represents running time. At this same time, the computer senses through input B and stores the initial speed (r.p.m.) of the collet spindle. The collet speed (rpm) is reduced during the fiber forming run in order to maintain the peripheral speed of the forming package substantially constant as the outside diameter of the package builds up. The bushing temperature is preferably maintained constant during the fiber forming run in order to obtain the most efficient fiber forming. It is believed to be better to maintain the bushing temperature constant and vary the collet r.p.m. to achieve constant fiber diameter rather than vice versa as described above in the discussion of the prior art.

The winder is stopped manually at the end of a predefined time or before that time if a fiber forming interruption occurs. If the fiber forming run continues for the predefined time, this is defined as a call down. The operator is informed of a call down by the flashing of light 50 on the position where the call down occurs. The winder is stopped by the operator pushing contact button 48. This also identifies by input D the next load cell input E with the particular position and moves the load cell 47 to a location adjacent to the particular position in order to receive the forming package for weighing. Since each load cell 47 services five or six positions, the pushing of the contact 48 also initiates another function wherein the computer calculates and controls the movement of the load cell according to the time sequence in which signals are received from each of the positions which the load cell serves.

The load cell 47 is supported on a carriage 52 which is carried by trolley 53 on monorail 54. The carriage 52 is moved horizontally on the monorail by a rotating screw 55 driven by motor 56. The screw passes through a threaded hangar bushing 57 mounted on the trolley 53. Rotation of screw 55 moves the carriage 52 in a vertical plane which is parallel to a thoeretical vertical plane which extends through the various forming positions located under a forehearth. The space 59 between these two planes is 4 to 6 feet in order to permit movement by the operator from one position to another without bumping into the load cell carriage 52. The forming package is mounted for weighing on package support 60 which is mechanically attached to the load cell 47. When the operator puts the forming package 46 on the support 60, he pushes the contact 45. This is the Read Weight Request contact which permits the computer to sense the load cell input E and in turn initiate a series of internal operations and output actions.

During the forming operation the collet speed is sensed at timed intervals, such as for example, every 5 minutes. Speed sensing is accomplished by measuring the amount of time (counting pulses) required for a specific number of pulses from input B to occur beginning with the first pulse sensed, each pulse representing one revolution of the winder collet. As each speed measurement is taken, it is tested for an out of limit condition with respect to a standard measurement (pulse count) which has been established in the computer through input F as part of the product code for that position.

As illustrated in FIG. 3 of the drawings, an updated speed slope, A,, is computed every 5 minutes from this information and stored. Should the wider operation be terminated before the next reading, this updated value is used in subsequent speed (yardage) calculations. If the five minutes are exceeded, a new updated value is calculated at the next speed reading and stored. This procedure is repeated, assuming no alarm condition has developed, until the operator stops the winder and the situation as shown in t, in FIG. 3 of the drawings is reached.

The value, A is obtained according to the following calculation:

F Q HH wherein:

A speed slope value S,,'= starting speed (r.p.m.)

S,= last speed (r.p.m.) reading n= running time at last reading i= last reading When the winder stops, the stoppage of the traverse motor is sensed and down time is again begun to be accumulated. Also, at this time, a finite total time, 1,, has been accumulated for the total winder running time at this particular position for the particular strand description. With this time reading, the average speed (r.p.m.) of the winder is calculated as follows:

41 o l wherein:

S,,= average winder speed (r.p.m.)

S initial winder speed (r.p.m.)

A,= last slope value calculated t,= total running time A standard average winder speed is calculated based on the standard winder speed curve established for the particular position through the product code. The standard winder speed corresponds in turn with a standard strand speed established by the product code. The actual strand speed is determined as follows:

YS= actual average strand speed S actual average winder speed (r.p.m.)

S standard average winder speed (r.p.m.)

YS= standard average strand speed The actual average strand speed as calculated above is utilized in. the calculation of the fiber diameter (yardage). This calculation is performed after the forming package is weighed on the load cell and the weight information is transmitted to the computer. The computer performs a scale tare check before the package is placed on the load cell and the tare weight is subtracted from the weight indicated by the load cell to give a true forming package weight. Based upon previously discussed product code information, a wet weight is calculated. The wet weight is recalculated to a dry weight, and a fiber diameter in terms of yards per pound is calculated as follows:

YD= yards per pound YS= actual average strand speed t,= time of forming run NGW= net glass weight If the calculated yardage (fiber diameter) is beyond specified limits, a bushing temperature correction is calculated by the computer as follows:

At=YD YDS/K wherein:

At= temperature correction F.

YD= actual yards per pound YDS= standard yards per pound K= temperature correction factor (yards/F.)

The temperature correction is typed by the typewriter 42 to provide the proper instructions to the bushing control room. The correction is made by an operator in the bushing control room before the next fiber forming run.

Concurrently with the yardage calculations of the computer, a signal is sent by the computer to the light signal panel 62. Depending upon the weight of the forming package, one or a combination of four signal lights 69 is turned on. The four lights, either independently or in combination, indicate (1) full package or greater, (2) between full and three-fourth package, (3) between three-fourth and one-half package, (4) between one-half and one-fourth package, and (5) one-fourth and less than one-fourth package. The computer 40 accumulates the weight by weight category (full package or less) for each position along with the number of entries made in each category.

The forming room operator removes the forming package 46 from the weighing support 60 and places it on the rack 70 v according to the weight category signaled by the lights 69 on light panel 62. The rack 70 contains package supports 71 which are suitably labeled or otherwise identified to support the forming packages according to the above-mentioned categories. The forming packages are then carried by the rack 70 on monorail 72 to an end-finding station where they are further segregated after end finding and sent to fabricating stations for manufacture into yarn, roving, chopped strand, reinforcing mat and other glass fiber products. The abovedescribed forming and handling sequence is then repeated.

The invention has been described with regard to forming glass fiber strand in a certain manner. The invention can be performed by changing the programming of the fiber forming variables in other conventional or obvious ways. For example, the winder speed can be kept constant and the bushing temperature varied during the fiber forming run as above discussed or the bushing temperature can be kept constant and the strand speed constant by a constant r.p.m. capstan as illustrated in US. Pat. No. 3,273,985. The computer can be connected to suitable circuits to provide automatic rather than manual adjustments of variables such as bushing temperature when they are out of specification.

The invention provides several major benefits to glass fiber strand formation. The continuous measurement of yardage (fiber diameter) and bushing temperature adjustment package by package provides much tighter control of the forming operation thereby resulting in improved yardage uniformity and substantially complete elimination of offyardage strand. The categorization of the forming packages by weight results in improved economies in subsequent operations where forming package size must be considered for optimum production. The monitoring of the forming process provides an improved means for pinpointing trouble spots in the forming operation. In addition, present production down time and quality control labor associated with present yardage sampling procedures are eliminated.

The above description of the invention and the details of its operation are intended to be exemplary and not limiting upon the scope of the invention except as set forth in the accompanying claims.

We claim:

1. In an apparatus for producing glass fibers which comprises a plurality of fiber forming apparatus, each comprising:

a. a container for holding molten glass,

b. means for issuing the molten glass from the container in the form of a plurality of streams,

c. means for attenuating the streams into cooled solidified fibers,

d. means for collecting the fibers in a forming package, and

e. means for conveying the forming package to an end-finding station, the improvement which comprises f. means for weighing said forming package comprising i. computer means programmed to respond to applied signals and to produce output signals according to a relationship which computes a forming package weight, compares the weight to a sequence of weight categories and describes each package according to a weight category,

ii. load cell means coupled with the computer means to transmit and apply a signal to the computer means,

iii. forming package supporting means coupled with the load cell means to cause the load cell means to transmit and apply a signal to the computer means upon the imposition of a forming package,

iv. data entry means to transmit and apply product code signals to the computer means,

v. output signal display means responsive to computer output signals, and

g. means for conveying said weighing means (f) to locations adjacent each of the plurality of fiber forming apparatus.

2. In the method of producing glass fibers which comprises producing glass fibers at a plurality of fiber forming positions according to a process which comprises:

a. providing molten glass in a container,

b. withdrawing the molten glass from the container in the form of a plurality of streams,

c. attenuating the streams and cooling them to solidify them into fine fibers by applying an attenuating force on the cooled fibers which is transmitted through the fibers to the streams as the fibers are moving at a high rate of speed,

d. collecting the fibers in a forming package on a rotating collet driven by a motor at a controlled speed, and

e. conveying the package to an end-finding station, the improvement which comprises f. programming a computer to receive load cell signals, product code signals, clock signals, motor status signals, and collet rotation signals, to compute in response to motor status signals and collet rotation signals, during fiber collection, an actual average collet winding speed, to compute from the actual average collet winding speed and the product code signals an actual average fiber speed, to compute a forming package weight from the load cell signals and product code signals, to compute an actual average fiber diameter from the forming package weight, the product code signals, and the clock signals, to compare the forming package weight and the actual average yarn diameter to weight and fiber diameter categories, and to produce an output signal defining the weight and fiber diameter category of the package,

g. transmitting from the rotating collet, during forming, to

the computer signals corresponding to each rotation,

h. transmitting from the motor to the computer running status signals,

. supporting the forming package on a load cell causing a signal to be transmitted to the computer, and in response thereto a package weight and fiber diameter category signal from the computer,

j. segregating the forming package in response to the computer output signal, and

k. conveying the segregated forming package to an endfinding station.

3. In the method of producing glass fibers which comprises producing glass fibers at a plurality of fiber forming positions according to a process which comprises:

a. providing molten glass in a container,

b. withdrawing the molten glass from the container in the form of a plurality of streams,

c. attenuating the streams and cooling them to solidify them into fine fibers by applying an attenuating force on the cooled fibers which is transmitted through the fibers to the streams as the fibers are moving at a high rate of speed,

d. collecting the fibers in a forming package on a rotating collet driven by a motor at a controlled speed, and

e. controlling the temperature of the molten glass in the container during the forming run, the improvement which comprises f. programming a computer to receive load cell signals, product code signals, clock signals, motor status signals, and collect rotation signals, to compute in response to motor status signals and collet rotation signals, during fiber collection, an actual average winding speed, to compute from the actual average winding speed and the product code signals an actual average fiber speed, to compute a package weight from the load cell signals and product code signals, to compute an actual average fiber diameter from the actual average fiber speed, the package weight, product code signals and the clock signals, to compare the actual average fiber diameter to a standard fiber diameter according to the product code signals, and to produce an output signal indicating fiber diameter category,

g. transmitting from the rotating collet, during forming, to

the computer signals corresponding to each rotation,

h. transmitting from the motor to the computer running status signals,

i. supporting the forming package on a load cell causing a signal to be transmitted to the computer, and

j. issuing a fiber diameter category signal from the computer.

4. The method described in claim 3 wherein the computer output signal indicates an adjustment to at least one of the control variables consisting of molten glass temperature and Si) and the adjustment is applied to at least one of the control variables consisting of molten glass temperature and motor speed prior So) next fiber forming run Ai) to minimize the variation of Ai=(So the standard Si)/ti tf) Sa) Sa=So-Aitf/ 5. The method described in claim 4 wherein the variable which is modified is the glass temperature 6. The method described in claim 3 wherein the speed of travel of the cooled fiber is obtained by periodically sensing colletrotation signals, computing a winding speed (Si) according to number of rotations for each period, computing from each successive winding speed and from the first computed winding speed (So) a speed slope (Ai) according to the relation: Ai=(S Si)/ti where ti is the elapsed winding time according to the clock signals then responsive to a motor status signal indicating completion of winding, using the last computed speed slope and the elapsed winding time according to the clock signals at completion of winding (tf), and computing an actual average winding speed (Sa) according to the relation: Sa=SoAitf/2.

7. In an apparatus for producing glass fibers which comprises:

a. a container for holding molten glass,

b. means for issuing the molten glass from the container in the form of streams,

c. means for attenuating the streams into cooled, solidified fibers moving at a high rate of speed,

d. means for collecting the cooled fibers in a forming package,

said means (c) and (d) comprising collet rotating means, motor driving means and means for controlling the speed of said motor driving means, and

e. means for controlling the temperature of the glass in the container, the improvement which comprises f. computer means programmed to respond to applied signals and to produce output signals according to a sequence of relationships which compute a forming package weight, a winding speed, therefrom a winding speed slope and an average actual winding speed, and a fiber forming time, and which therefrom compute an average actual fiber diameter and compare said average actual fiber diameter with a standard diameter,

g. load cell means coupled with the computer means to transmit and apply a signal to the computer means, forming package supporting means coupled with the load cell means to cause the load cell means to transmit and apply a signal to the computer means upon the imposition of a forming package,

. data entry means to transmit and apply product code signals to the computer means,

j. collet rotation signal means coupled with the collet rotating means to transmit and apply rotation signals to the computer means corresponding to each rotation of the collet rotating means,

k. motor status signal means coupled with the motor driving means to transmit and apply status signals to the computer means, and

. means coupled with the computer means and responsive to the computer output signals to indicate a fiber diameter category.

8. The apparatus describe in claim 7 including:

' m. means to adjust at least one of the temperature controlling means and fiber speed means to minimize the variation of the cooled fiber diameter from the standard diameter.

9. The apparatus described in claim 7 wherein the programmed computer means for computing a winding speed, a

winding speed slope and an average actual winding speed comprises means for computing a winding speed Si) accordmg to a number of collet rotations in a time perio means for computing from each successive winding speed and from the first computed winding speed (So) a speed slope (Ai) wherein said speed slope computing means is characterized according to the relation: A'F(SoSi)/t, where t, is the elapsed winding time of the time periods and means for computing an average actual winding speed (Sa) from a last computed speed slope at the conclusion of winding wherein said average actual winding speed computing means is characterized according to the relation: Sa=SoA,t,/2 where t, is the elapsed winding time of the time periods to the conclusion of winding.

10. The apparatus described in claim 7 wherein the means for transmitting and applying signals and the computer means for producing computer output signals are electronic means for providing signals in the form of electronic signals.

:IUNITED' STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,652,243 Dated March 28, 1972 Inventofls) Thomas Jensen" and. Howard M. Bennett It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 4, Column 9, lines 6 through 9 should read e--motor speed and the adjustment is applied to at least one of the control variables consisting of molten glass temperature and motor speed prior to the next fiber forming run in order to minimize the variation of the fiber diameter from the standard fiber diameter.

Signed and sealed this 8th day of August 19 72 (SEAL) Att'est:

EDWARD .M.FLE TCHER ,JR. ROBERT GOTTSCHALK Attest'ing Officer Commissioner of Patents FORM PO-1050 (10-69) USCOMMQDC 60376-5 69 us. GOVERNMENT PRINTING OFFICE: 1969 o--36s-3J4 UNITED STATES PATENT OFFICE I CERTIFICATE OF CORRECTION Patent No. 3, 652, 243 Dated March 28; 1972 Inventor(s) Thomas H. Jensen and Howard M. Bennett It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 4, Column 9, lines 6 through 9 should read ---motor speed and the adjustment is applied to at least one of the control variables consisting, of molten glass temperature and motor speed prior to the next fiber forming run in order to minimize the variation of the fiber diameter from the standard fiber diameter.

Signed and sealed this 8th day of August 1972.

(SEAL) Att'est:

EDWARD I I.FI.E3TCHER,JR. ROBERT GOTI'SCHALK Attest'ing Officer Commissioner of Patents FORM PO-1050 (10-69) USCOMM-DC 6O376-P69 us. GOVERNMENT PRINTING OFFICE: I969 0-366-334 

1. In an apparatus for producing glass fibers which comprises a plurality of fiber forming apparatus, each comprising: a. a container for holding molten glass, b. means for issuing the molten glass from the container in the form of a plurality of streams, c. means for attenuating the streams into cooled solidified fibers, d. means for collecting the fibers in a forming package, and e. means for conveying the forming package to an end-finding station, the improvement which comprises f. means for weighing said forming package comprising i. computer means programmed to respond to applied signals and to produce output signals according to a relationship which computes a forming package weight, compares the weight to a sequence of weight categories and describes each package according to a weight category, ii. load cell means coupled with the computer means to transmit and apply a signal to the computer means, iii. forming package supporting means coupled with the load cell means to cause the load cell means to transmit and apply a signal to the computer means upon the imposition of a forming package, iv. data entry means to transmit and apply product code signals to the computer means, v. output signal display means responsive to computer output signals, and g. means for conveying said weighing means (f) to locations adjacent each of the plurality of fiber forming apparatus.
 2. In the method of producing glass fibers which comprises producing glass fibers at a plurality of fiber forming positions according to a process which comprises: a. providing molten glass in a container, b. withdrawing the molten glass from the container in the form of a plurality of streams, c. attenuating the streams and cooling them to solidify them into fine fibers by applying an attenuating force on the cooled fibers which is transmitted through the fibers to the streams as the fibers are moving at a high rate of speed, d. collecting the fibers in a forming package on a rotating collet driven by a motor at a controlled speed, and e. conveying the package to an end-finding station, the improvement which comprises f. programming a computer to receive load cell signals, product code signals, clock signals, motor status signals, and collet rotation signals, to compute in response to motor status signals and collet rotation signals, during fiber collection, an actual average collet winding speed, to compute from the actual average collet winding speed and the product code signals an actual average fiber speed, to compute a forming package weight from the load cell signals and product code signals, to compute an actual average fiber diameter from the forming package weight, the product code signals, and the clock signals, to compare the forming package weight and the actual average yarn diameter to weight and fiber diameter categories, and to produce an output signal defining the weight and fiber diameter category of the package, g. transmitting from the rotating collet, during forming, to the computeR signals corresponding to each rotation, h. transmitting from the motor to the computer running status signals, i. supporting the forming package on a load cell causing a signal to be transmitted to the computer, and in response thereto a package weight and fiber diameter category signal from the computer, j. segregating the forming package in response to the computer output signal, and k. conveying the segregated forming package to an end-finding station.
 3. In the method of producing glass fibers which comprises producing glass fibers at a plurality of fiber forming positions according to a process which comprises: a. providing molten glass in a container, b. withdrawing the molten glass from the container in the form of a plurality of streams, c. attenuating the streams and cooling them to solidify them into fine fibers by applying an attenuating force on the cooled fibers which is transmitted through the fibers to the streams as the fibers are moving at a high rate of speed, d. collecting the fibers in a forming package on a rotating collet driven by a motor at a controlled speed, and e. controlling the temperature of the molten glass in the container during the forming run, the improvement which comprises f. programming a computer to receive load cell signals, product code signals, clock signals, motor status signals, and collet rotation signals, to compute in response to motor status signals and collet rotation signals, during fiber collection, an actual average winding speed, to compute from the actual average winding speed and the product code signals an actual average fiber speed, to compute a package weight from the load cell signals and product code signals, to compute an actual average fiber diameter from the actual average fiber speed, the package weight, product code signals and the clock signals, to compare the actual average fiber diameter to a standard fiber diameter according to the product code signals, and to produce an output signal indicating fiber diameter category, g. transmitting from the rotating collet, during forming, to the computer signals corresponding to each rotation, h. transmitting from the motor to the computer running status signals, i. supporting the forming package on a load cell causing a signal to be transmitted to the computer, and j. issuing a fiber diameter category signal from the computer.
 4. The method described in claim 3 wherein the computer output signal indicates an adjustment to at least one of the control variables consisting of molten glass temperature and motor speed and the adjustment is applied to at least one of the control variables consisting of molten glass temperature and motor speed prior to next fiber forming run in order to minimize the variation of the fiber diameter from the standard fiber diameter.
 5. The method described in claim 4 wherein the variable which is modified is the glass temperature.
 6. The method described in claim 3 wherein the speed of travel of the cooled fiber is obtained by periodically sensing collet rotation signals, computing a winding speed (Si) according to number of rotations for each period, computing from each successive winding speed and from the first computed winding speed (So) a speed slope (Ai) according to the relation: Ai (So -Si)/ti where ti is the elapsed winding time according to the clock signals then responsive to a motor status signal indicating completion of winding, using the last computed speed slope and the elapsed winding time according to the clock signals at completion of winding (tf), and computing an actual average winding speed (Sa) according to the relation: Sa So- Aitf/2.
 7. In an apparatus for producing glass fibers which comprises: a. a container for holding molten glass, b. means for issuing the molten glass from the container in the form of streams, c. means for Attenuating the streams into cooled, solidified fibers moving at a high rate of speed, d. means for collecting the cooled fibers in a forming package, said means (c) and (d) comprising collet rotating means, motor driving means and means for controlling the speed of said motor driving means, and e. means for controlling the temperature of the glass in the container, the improvement which comprises f. computer means programmed to respond to applied signals and to produce output signals according to a sequence of relationships which compute a forming package weight, a winding speed, therefrom a winding speed slope and an average actual winding speed, and a fiber forming time, and which therefrom compute an average actual fiber diameter and compare said average actual fiber diameter with a standard diameter, g. load cell means coupled with the computer means to transmit and apply a signal to the computer means, h. forming package supporting means coupled with the load cell means to cause the load cell means to transmit and apply a signal to the computer means upon the imposition of a forming package, i. data entry means to transmit and apply product code signals to the computer means, j. collet rotation signal means coupled with the collet rotating means to transmit and apply rotation signals to the computer means corresponding to each rotation of the collet rotating means, k. motor status signal means coupled with the motor driving means to transmit and apply status signals to the computer means, and l. means coupled with the computer means and responsive to the computer output signals to indicate a fiber diameter category.
 8. The apparatus describe in claim 7 including: m. means to adjust at least one of the temperature controlling means and fiber speed means to minimize the variation of the cooled fiber diameter from the standard diameter.
 9. The apparatus described in claim 7 wherein the programmed computer means for computing a winding speed, a winding speed slope and an average actual winding speed comprises means for computing a winding speed (Si) according to a number of collet rotations in a time period, means for computing from each successive winding speed and from the first computed winding speed (So) a speed slope (Ai) wherein said speed slope computing means is characterized according to the relation: Ai (So- Si)/ti where ti is the elapsed winding time of the time periods and means for computing an average actual winding speed (Sa) from a last computed speed slope at the conclusion of winding wherein said average actual winding speed computing means is characterized according to the relation: Sa So-Aitf/2 where tf is the elapsed winding time of the time periods to the conclusion of winding.
 10. The apparatus described in claim 7 wherein the means for transmitting and applying signals and the computer means for producing computer output signals are electronic means for providing signals in the form of electronic signals. 